当我更新可观察数组WPF时，Datagrid行模板中的Datagrid不会更新

Question

我绑定了DataGrid中的值列表。 添加了datagrid行模板。当选择的行我显示该模板。在我的模板中，我有一个DataGrid具有不同的列表（ObservableCollection）。 Array具有价值，但未在DataGrid中更新。

我的代码：

XAML

  <DataGrid IsReadOnly="True" ItemsSource="{Binding Patients}" Grid.Row="1" Grid.Column="0" AutoGenerateColumns="False" CanUserResizeColumns="True" CanUserReorderColumns="False"
                  SelectedItem="{Binding SelectedPatient}"  SelectionMode="Single">
            <DataGrid.InputBindings>
                <MouseBinding
                   MouseAction="LeftDoubleClick"
                   Command="{Binding SingleClickCommand}" CommandParameter="{Binding ElementName=myGrd, Path=SelectedPatient}" />
            </DataGrid.InputBindings>
            <DataGrid.Columns>

                <DataGridTextColumn Header="#" Binding="{Binding Salutation}"  Width="*"/>
                <DataGridTextColumn Header="FirstName" Binding="{Binding FirstName}"  Width="*"/>
                <DataGridTextColumn Header="LastName" Binding="{Binding LastName}"  Width="*"/>
                <DataGridTextColumn Header="Gender" Binding="{Binding Gender}"  Width="*"/>
                <DataGridTextColumn Header="Age" Binding="{Binding Age}"  Width="*"/>

            </DataGrid.Columns>
            <DataGrid.RowDetailsTemplate>
                <DataTemplate>
                    <DockPanel Background="GhostWhite">

                        <Grid Margin="30,10,30,0">
                            <Grid.RowDefinitions>
                                <RowDefinition Height="*"/>
                                <RowDefinition Height="*"/>
                            </Grid.RowDefinitions>
                            <Grid.ColumnDefinitions>
                                <ColumnDefinition Width="*"/>
                                <ColumnDefinition Width="*"/>
                            </Grid.ColumnDefinitions>
                            <Grid Grid.Row="1" Grid.Column="0" Margin="0,0,0,50">
                                <Grid.RowDefinitions>
                                    <RowDefinition Height="*"/>
                                </Grid.RowDefinitions>
                                <Grid.ColumnDefinitions>
                                    <ColumnDefinition Width="*"/>
                                </Grid.ColumnDefinitions>
                                <DataGrid IsReadOnly="True"  Grid.Row="0" Grid.Column="0" AutoGenerateColumns="False" CanUserResizeColumns="False" CanUserReorderColumns="False" ItemsSource="{Binding PatientVisits}">
                                    <DataGrid.Columns>
                                        <DataGridTextColumn Header="Visit Date" Width="Auto" Binding="{Binding Complaint}"/>
                                        <DataGridTextColumn Header="Medication" Width="Auto"   Binding="{Binding Medication}"/>
                                    </DataGrid.Columns>
                                </DataGrid>
                            </Grid>
                        </Grid>
                    </DockPanel>
                </DataTemplate>
            </DataGrid.RowDetailsTemplate>
        </DataGrid

Cs代码 我在行选择上添加了以下代码

   public void GetVisitHistoryForSelectedPatient()
        {
            PatientVisits = new ObservableCollection<StudyVisitModel>
            {
               new StudyVisitModel{VisitDate=DateTime.Now,Medication="Tablets and tonics"},
               new StudyVisitModel{VisitDate=DateTime.Now,Medication="Tablets and tonics"}
            };
            OnPropertyChanged("PatientVisits");
        }